James Webb Space Telescope FINALLY Detects First Signal.
What Did it Find?
Intro NASA's James Webb Space Telescope is an infrared
space observatory that launched on Dec 25, 2021, from ESA's launch site at Kourou in
French Guiana on board an Arianespace Ariane 5 rocket.
The $10 billion telescope, which happens to be NASA's most powerful space science telescope
ever, is tasked with probing the cosmos to uncover the history of the universe from the
Big Bang to alien planet formation and beyond.
After much anticipation, the telescope has finally detected its first signal among the
stars!
Let's talk about how this came to be and what the telescope found.
The James Webb Space Telescope According to NASA, the James Webb Space Telescope
will focus on four main areas.
It will look to study the first light in the universe, the assembly of galaxies in the
early universe, the birth of stars and protoplanetary systems, and planets.
Since its launch, the observatory has undergone a series of science and calibration tests
including sunshield deployment, telescope deployment, instrument turn-on, and telescope
alignment.
The James Webb Space Telescope is the product of an impressive international collaboration
between NASA, the European Space Agency, and the Canadian Space Agency.
According to NASA, the research for JWST involved over 300 universities, organizations, and
companies across 29 U.S. states and 14 countries.
The nominal duration for the telescope is five years but the goal is to stretch it to
10 years.
The telescope is expected to study the early stages of the universe after the Big Bang
started the universe as we know it today.
In the first stages after the Big Bang, the universe was a sea of particles such as electrons,
protons, and neutrons.
This is why the light was not visible until the universe cooled enough for these particles
to begin combining.
Another thing JWST will study is what happened after the first stars formed; this era is
called "the epoch of reionization" because it refers to when neutral hydrogen was re-ionized
by radiation from these first stars.
Looking at galaxies is a useful way to see how matter is organized on gigantic scales,
which in turn gives us hints as to how the universe evolved.
The spiral and elliptical galaxies we see today evolved from different shapes over billions
of years, and one of JWST's goals is to look back at the earliest galaxies to better understand
that evolution.
Scientists are also trying to figure out how we got the variety of galaxies that are visible
today and the current ways that galaxies form and assemble.
The last decade has seen vast numbers of exoplanets discovered, including with NASA's planet-seeking
Kepler Space Telescope.
JWST's powerful sensors will be able to peer at these planets in more depth, including
imaging their atmospheres.
Understanding the atmospheres and the formation conditions for planets could help scientists
better predict if certain planets are habitable or not.
The First Signal NASA has announced that the telescope finally
captured its first grainy images of a distant star.
The first images taken by the space observatory have identified starlight for the first time
using its NIRCam instrument which is also responsible for helping keep its primary mirror's
segments aligned.
Webb's first image of the sky was taken in the very early morning of Feb. 2, 2022.
The image shows a star called HD 84406.
The starlight was seen through each of Webb's 18 mirror segments in its primary mirror,
so the resulting image shows a mosaic of 18 scattered bright dots.
As Webb aligns and focuses over the next few months, these 18 dots will slowly become a
single star.
To make this image happen, the team had to factor in how misaligned the mirror segments,
which are slowly and carefully aligning, were at the time.
Since not all the segments were facing the same direction.
This required the team to capture many images of this region of the sky to find the starlight
with all 18 segments.
Webb captured more than 1,500 images in total in this first observation.
Additionally, this process required many Webb systems to act together as an observatory
for the first time in flight.
Even in this preliminary image, the initial results are very similar to the simulations
performed by scientists before the telescope launched.
This mission milestone is not taken lightly by the astronomical community.
The space telescope faced decades of challenges and delays and after launch, had to undergo
a risky deployment with hundreds of "single-point failures" that could've doomed the mission.
But now, safely unfolded and at its destination in space, this incredible early data from
Webb has sparked cautious but overwhelming excitement from scientists around the globe.
Webb will continue to align and focus its mirror segments so that they all act as one
and can laser-focus their view on distant cosmic objects.
The Hunt for Alien Life As exciting as these first few images may
be, they are merely the start of an exciting journey for the telescope which will see it
explore everything from the start of the universe to studying distant planets.
JWST will see the universe primarily in infrared light.
Once its hulking golden eye opens, the observatory's exquisite sensitivity will allow the telescope
to spy on the faint, faraway signatures of the first stars and galaxies that populated
the universe.
That sensitivity will also help it directly observe alien worlds—though nobody could
have planned to use the telescope for this purpose when it was designed.
When JWST was conceived in 1989, planets orbiting other stars had not yet been discovered.
Planet formation theories suggested such worlds should exist, but the first exoplanets weren't
announced until 1992.
Recently, exoplanet-hunters such as NASA’s Kepler space telescope have revealed that
worlds orbiting other stars in the Milky Way are as common as grains of sand on Earth.
That abundance affords the JWST team a remarkable opportunity to study some of the most intriguing
worlds in detail.
By blocking the light of planets’ parent stars with an instrument called a coronagraph,
JWST can directly image some of these faint, faraway worlds in orbit—even those that
might still be forming.
The telescope can peer through alien atmospheres and determine what the gassy shrouds are made
of and how they’ve evolved over a planet’s lifetime.
And it can read molecular signatures in the day-side glow of planets.
After around 6 months into its mission, JWST will begin drinking in starlight and studying
faraway worlds.
As planets pass between their stars and the telescope, for a brief moment their atmospheres
will appear in silhouette, illuminated by the starlight shining through from behind.
In that starlight, Webb will read the signatures of the gasses the light passed through.
Studying Planetary Atmospheres A grab-bag of extreme systems and planetary
oddballs are among Webb’s early transiting targets, including WD 1856b, a giant planet
that orbits a stellar corpse, and HD 80606b, a planet whose orbit looks more like a comet’s
elongated, lopsided loop around its star than a planet’s more circular path.
Those extreme systems could contain clues about how different kinds of planets form
and survive, and by surveying the gasses clinging to a multitude of worlds, JWST will help scientists
understand how a planet’s size, temperature, and evolution are linked to its climate and
other characteristics.
Many of the telescope’s early observations will target hot Jupiters, a class of planets
we don’t see in our solar system.
Whipping around their stars in mere hours or days, these giant worlds are among the
most common types of planets discovered so far by astronomers.
The researchers will put all four of the telescope's instruments through their paces, and they
will look for the ratio of carbon and oxygen in the planets' atmospheres, which contains
information about where the planets formed.
Another intriguing type of planet that we don't see in the solar system is the super-Earth
or the mini-Neptune—worlds that are bigger than Earth and smaller than Neptune, like
Gliese 486b, GJ 1132b, and K2-18b.
Finding out whether these planets have atmospheres, and what those atmospheres are made of, is
crucial for determining whether they might be habitable.
Whether such worlds could be habitable hinges on where and how they formed and how they
evolved.
Some could be the stripped cores of former Neptunes which dims the odds for habitability.
Others sit right on the border between large rocky worlds and small gas worlds–a transition
that scientists don't fully understand.
Other early targets include hot rocky planets that are snuggled up to their stars, making
them more like roasted lumps of charcoal than overheated puffballs.
On these worlds, which include 55 Cancri e and K2-141b, clouds made of rock and minerals
might rain lava, creating a landscape that defies imagination.
JWST will also target each of the seven rocky, roughly Earth-size worlds in the TRAPPIST-1
system.
These planets orbit a small, nearby star about the size of Jupiter, and three of them are
temperate.
TRAPPIST-1e, among the early targets, offers perhaps the best chance of detecting Earth-like
conditions, while TRAPPIST-1c, another early target, is closer to its star and probably
Venus-like in temperature.
While JWST will transform our understanding of the worlds that populate our galaxy, the
telescope is unlikely to spot signs of life—unless scientists are extremely lucky.
That type of observation is just on the edge of the telescope’s capabilities, and it
would require an oversized chunk of observing time.
Detecting distant alien biosignatures means looking for combinations of gasses or chemical
elements that scientists wouldn’t expect geologic processes alone to produce.
And while astrobiologists have some ideas about what we could look for—methane, ozone,
and other metabolic byproducts—it’s not clear what form alien life’s signatures
might take.
Outro If you found this video informative, you may
also like this one about the LUVOIR mission which is scheduled to be the successor to
the James Webb Space Telescope.
Do you think the JWST will finally find signs of extraterrestrial life?
Please share your thoughts in the comments section below.